>> I also created a wiki page to keep track of the status, the TODOs and still
>> pending questions...
>
> The Questions section says "restrict to https://", which is curious given
> that Section 6 of draft-ietf-doh-dns-over-https-11 says " This protocol MUST
> be used with the https scheme URI".

I know it says that, but I didn't add this restriction yet in code and
previously in curl history it has been convenient at times to allow some
"slack" for some "MUST"s to allow for easier debugging and testing, at least
during a period when the protocol is young, so I could be open for discussing
that...